1. Buckingham AD (1978) In: Pullman B (ed) Intermolecular interactions: From diatomics to biopolymers, vol I. Wiley, New York, p 1
2. Hurst GJB, Fowler PW, Stone AJ, Buckingham AD (1986) Int J Quantum Chem 29:1223
3. Tang KT, Toennies JP (1984) J Chem Phys 80:3726
4. Liptay W (1974) In: Lim EC (ed) Excited states, vol I. Academic Press, New York
5. Baumann W (1989) In: Rossiter BW, Hamilton JF (eds) Physical methods of chemistry, vol IIIB. Wiley, New York, p 45 and references therein